Digestion is a process where the complex food particles are broken down to smaller particles so that they can be absorbed by blood and transported all over the body. There are many organs involved in the process of digestion. They release different enzymes to digest different nutrients like carbohydrates, proteins and fats.

Food pipe or oesophagus is a part of the alimentary canal of the digestive system. It helps to transfer bolus from the mouth to stomach. The muscular wall of the food pipe performs involuntary movement called peristalsis that helps to push the food forward.

Villus or Villi are the small finger-like projections on the inner wall of the small intestine. Villi contain microvilli which increase the surface area of the intestinal walls for absorption. The villi have a thin wall made up of a single layer of epithelial cells and also have a rich supply of blood and lymph capillaries. This helps in rapid absorption of digested nutrients from the lumen of the small intestine into the blood or lymph circulation.

The digested products of fats are insoluble in water and hence cannot be absorbed into the blood. The aggregates of these compounds are converted into small water-soluble droplets called micelles. These micelles are further converted in the intestinal mucosal cells into smaller protein-coated particles called chylomicrons. These particles are absorbed into a special set of lymph capillaries called lacteal, which helps in absorption of digested fats.